distribute	reads
0-500	28021
500-800	15738
800-1000	8670
1000-1200	8268
1200-1400	7294
1400-1600	6506
1600-1800	5875
1800-2000	5416
2000-2200	5116
2200-2400	4513
2400-2600	4246
2600-2800	3973
2800-3000	3715
>3000	63718
